Bovesecchi G, Coppa P, Pistacchio S
Industrial Engineering Department, University of Rome "Tor Vergata," Via del Politecnico 1, 00133 Roma, Italy.
Rev Sci Instrum. 2018 May;89(5):055107. doi: 10.1063/1.5019776.
A new thermal conductivity probe for high temperature (HT-TCP) has been built and tested. Its design and construction procedure are adapted from the ambient temperature thermal conductivity probe (AT-TCP) due to good performance of the latter device. The construction procedure and the preliminary tests are accurately described. The probe contains a Pt wire as a heater and a type K thermocouple (TC) as a temperature sensor, and its size is so small (0.6 mm in diameter and 60 mm in length) as to guarantee a length to diameter ratio of about 100. Calibration tests with glycerol for temperatures between 0 °C and 60 °C have shown good agreement with literature data, within 3%. Preliminary tests were also carried on a ternary molten salt for Concentrated Solar Power (CSP) (18% in mass of NaNO, 52% KNO, and 30% LiNO) at 120 °C and 150 °C. Obtained results are within λ range of the Hitec salt (53% KNO, 7% NaNO, 40% NaNO). Unfortunately, at the higher temperature tested (200 °C), the viscosity of the salt highly decreases, and free convection starts, making the measurements unreliable.
一种新型高温热导率探头（HT-TCP）已制造并测试完毕。由于环境温度热导率探头（AT-TCP）性能良好，其设计和制造流程借鉴于此。文中准确描述了制造流程和初步测试情况。该探头包含一根作为加热器的铂丝和一个作为温度传感器的K型热电偶（TC），其尺寸非常小（直径0.6毫米，长度60毫米），以确保长径比约为100。在0°C至60°C温度范围内用甘油进行的校准测试表明，与文献数据吻合良好，误差在3%以内。还在120°C和150°C下对用于聚光太阳能发电（CSP）的三元熔盐（质量分数为18%的NaNO、52%的KNO和30%的LiNO）进行了初步测试。所得结果在希泰克盐（53% KNO、7% NaNO、40% NaNO）的λ范围内。不幸的是，在测试的较高温度（200°C）下，盐的粘度大幅下降，开始出现自由对流，导致测量结果不可靠。
